Lubricating composition



has

LUBRICATING Coll/[POSITION Carl F. Prutton, Cleveland Heights, Ohio, assignor, by mesne assignments, to The Lubri-Zol Development Corporation, Cleveland, Ohio, a corporation of Delaware N Drawing. Application March 1, 1939,

Serial No. 259,230

16 Claims. (Cl. 252-54) This application is a u i n i p of In the case of gear lubrication, particularly my Copending applications Serials s- 737,070, when the lubricant is exposed to elevated temfi y 26, 1934; 8 filed December 4, peratures', there is a tendency to form similar de- 1934, a d 9 fi ed u st 1936, now Patposits. Such deposits cause similar diificulties, e t No- 5 5 and particularly in the case of heavily loaded This invention relates, as indicated, to lubrigears, cause damage to the gear teeth surfaces eating compositions, and more particularly to since the deposit is likely to cause mis-alignment compositions for use in connection with the when precipitated on the gear surfaces or bearlubrication of h Working par s f n rn ming failures When precipitated in the oil passages. on g motor vehicles, etc., and it is It has been discovered that the sludge and among the j s of s invention to provide other deposits which form in the lubricating oil compositions obviating the disadvantages of the on use contain two predominant components usual p troleum oils. comprising (1) polymerized hydrocarbons and When n s in the crankcase Of an (2) more or less oxidized polymerized hydrocarmobile, for example, it is a well-known fact that bons These components t as cementing oils deteriorate, forming considerable quantities agents for small particles of inorganic and of {gummy and semisohd materials- These soluble materials, greatly impairing the lubricattenals may deposlt on the metal Parts with ing effect of the oil. I have found that the best which the lhhhcaht comes ihhohhach in form solvents for one component of these deposits are of gummy resmOus- VarmSh-hke deposlts not the best for the other. For addition to a they may remain to some extent suspended in lubricating oil it is obvious that solvents must the body of the lhbhcaht f 5 the hasis be found which are mutually compatible, soluble for the accumulation of dirt, metallic particles, miscible in the on and which will dissolve the and other foreign matter to form sludge.

two components of the deposits previously re- These deposlts thlcken the Increase ferred to. By lubricating oils are meant mineral tion, lower the general efficienc of the engine, and make necessary more freque ht drainage and 0115 their synthetlc eqmvalents'. replacement of the lubricant. In aggravated h therefor? among h oblect? of h form, they may even cause failure of an engine venhon to phovlde lhbncaht Wm not due to sticking of the pistons in the cylinders, or readhy lose. Its .lubhcatmg quahties and .sufier bearing failures resulting from plugged oil pasother detenohatmn .sludhe Sages and the like I Another ob ect of this invention is to provide In winter, the passage of Small amounts of a lubricating composition which will not readily gasoline into the crank case of an engine often lose luhncahhg qhahhes due to results in the precipitation of sludge materials formatioh Whl also have extreme pressure which are particularly objectionable since they charactenshcs' hinder lubrication of the engine on starting, It is also among the objects of this invention causing undue wear and starting trouble. to provide a lubricating mineral oil which will viously an 1 which s t ludge under such resist deterioration due to sludge formation and conditions, would be especially desirable for win- 40 which Will be especially e c e under conditer use. The frequent oil changes necessary at tions f extreme Pressureall times of the year in order to keep an engine other Objects of the invention l appear as operating efiiciently and without danger of inthe description p ceeds.

jury are a major source of expenseand annoy- Tolthe accomplishment of the foregoing and ance, related ends, said invention, then, consists of the comprising this invention will preferably and for best results have certain physical and chemical characteristics which especially adapt the same for use in conjunction with the principal types of engines in use today, and for other uses.

The solvent components of the lubricant should beof fairly low volatility, i. e., with a vapor pressure at a temperature of 140 C. of below atmospheric, or preferably a vapor pressure less than atmospheric ata temperature of 170 C. In one embodiment of my invention now in commercial use, one component of my new solvent has a vapor pressure less than atmospheric at a temperature above 300 C. A mixture of two components, one with a vapor pressure a' little below atmospheric at 170 C. and the other with a vapor pressure a little below atmospheric at 350 C., has proven highly satisfactory.

Oxygen-free component I have found that of the entire class of halogenated oxygen-free organic compounds usable as a component of the solvent constituent in my new lubricant, as above defined, the halogenated hydrocarbons and generally those of the arcmatic series are to be preferred for most purposes as solvents for the unoxidized polymerized hydrocarbon deposit. Throughout this application, the term aromatic series is intended to include homologs as well. As hereinafter pointed out, however, certain of the aliphatic compounds of this type areparticularly useful for certain purposes.

In the case of the halogenated aromatic oxygen-free compounds, it is generally preferable that the halogen be attached to a carbon atom of the benzenoid ring. These latter compounds are usually more desirable because of their noncorrosive character and general stability.

. The halogenated oxygen-free organic compounds, as noted, may be either:

A. Aliphatic, such as halogenated:

I. Hydrocarbons,

Notably, those chlorinated or fluorinated hydrocarbons which contain from four to ten or more carbon atoms, e. g. Fluorinated hexane Fluorinated octane Fluorinated decan II. Amines III. Nitriles, e. g.

Chlorinated or fiuorinated:

Ethyl cyanide Butyl cyanide Octyl cyanide Lauryl nitrile Stearyl nitrile IV. sulphides, e. g.

Chlorinated or fluorinated:

Di-ethyl sulphide Di-butyl sulphide Di-octyl sulphide Di-amyl sulphide Di-lauryl sulphide Di-cetyl sulphide V. Mercaptans, e. g.

Chlorinated or fiuorinated:

Lauryl mercaptan Cetyl mercaptan Carnaubyl mercaptan Ceryl mercaptan Montanyl mercaptan Melissyl mercaptan Myricyl mercaptan VI. Thiocyanates (rhodanates) e. g.

Chlorinated or fiuorinated:

Ethyl thiocyanate Butyl thiocyanate Lauryl thiocyanate Cetyl thiocyanate Ceryl thiocyanate or the more generally preferable:

'8. Cyclic compounds, such as halogenated:

I. Benzene and related compounds such as:

(1) Halogenated benzene, e. g.

(a) Chlorinated benzene, e. g.,

The dichlorbenzenes, notably the ortho compound (b) Brominated benzene, e. g.

Ortho-dibrom benzene (c) Fluorinated benzene (2) Halogenated derivatives of benzene such as:

Mono-chlor aniline (preferably the ortho-compound) Mono-chlor dimethyl aniline Chlorinated toluidines Chlorinated xylidines Chlorinated diphenylamine (c) Halogenated hydrobenzenes, e. g. Hydrogenated dichlor-benzenes Dichlorhexahydrobenzene (dichlor cyclohexane) II. Polyphenyls, and related compounds, in-

cluding diphenyl, diphenyl benzenes, etc., such as (1) Halogenated diphenyl, e. g.

(a) Chlorinated diphenyl, e. g.

Mono-chlor diphenyls Di-chlor diphenyls Tri-chlor diphenyls (b) Brominated diphenyl, e. g. The mono-brom diphenyls (c) Fluorinated diphenyl (2) Halogenated derivatives of diphenyl,

such as, (a) Halogenated homologs of diphenyl,

e. g. Chlorinated phenyl toluenes Ethylated, or propylated, chlorinated diphenyl, e. g. di-ethyl tetrachlor diphenyl (b) Halogenated amino derivatives of diphenyl, e. g. Chlorinated phenyl-anilines Chlorinated phenyl-toluidines Chlorinated diphenyl amines (xenyl amines) (c) Halogenated hydrodiphenyls, e. g.

Chlorinated phenyl hexahydrobenzene Chlorinated dodecahydrodiphenyl III. Naphthalene and related compounds, such (l) Halogenated naphthalene (a) Chlorinated naphthalene, e. g.

zx-IIlOllO-ChlOI' naphthalene (b) Brominated naphthalenes, e. g;

oz-IIlOl'lO-blOIIl naphthalene (c) Fluorinated naphthalene (2) Halogenated derivatives of naphthalenes, such as: (a) Halogenated homologs of naphthalenes, e. g. Chlorinated methyl naphthalenes,

such as a-methyl naphthalene Chlorinated ethyl, propyl, or isopropyl naphthalenes -(b) Halogenated amino derivatives of naphthalene, e. g. Chlorinated naphthylamines Mono-chlor naphthyl amine (c) Halogenated hydronaphthalenes,

e. g. Chlorinated decahydronaphthalene Chlorinated tetrahydronaphthalene IV. Phenanthrene and anthracene and related compounds, such as:

(l) Chlorinated phenanthrene, chlorinated anthracene (2) Halogenated derivatives of phenanthrene and anthracene, such as:

( a) Halogenated homologs, e. g.

Chlorinated l-methyl phenanthrene Chlorinated 3-methyl phenanthrene Chlorinated 9,10 dimethyl phenanthrene Chlorinated propyl and isopropyl de rivatives of phenanthrene such as retene Chlorinated dimethyl anthracenes Chlorinated a-methyl anthracene Chlorinated e-methyl anthracene Chlorinated propyl and isopropyl derivatives of anthracene including their derivatives, such as homologs, amino derivatives and other substitution products. V

VI. Bridged ring compounds, such as the terpenes and related compounds, and their derivatives, e. g. chlorinated pinene.

VII. Heterocyclic compounds, such as pyridine, quinoline, pyrrole, thiophene, and derivatives of them, e. g. mono-chlor pyridine.

VIII. Nitriles derived from any of the above compounds, e. g.

Chlorinated:

' Benzonitrile Tolunitriles Benzyl cyanide N aphthyl cyanide Xenyl cyanide Cyclohexyl cyanide IX. sulphides derived from any one of the above compounds, e. g.

Chlorinated: 33 Diphenyl sulphide Dibenzyl sulphide Dixylyl sulphides Di-naphthyl sulphides Dixenyl sulphides Dicyclohexyl sulphide.

X. Mercaptans derived from any of the above compounds, e. g.

Chlorinated:

Benzyl mercaptan Phenyl benzyl mercaptans Naphthyl mercaptans Phenyl propyl mercaptans Cyclohexyl mercaptan XI. Thiocyanates; e. g.

, Chlorinated:

Benzyl thiocyanate Phenyl ethyl thiocyanate Phenyl propyl thiocyanate Cyclohexyl thiacyanate It will be noted that the above enumerated examples of the organic ring compounds which are usually preferred are, in general, compounds of zenoid ring structures and also of the type in which the halogen is directly attached to an atom which is a part of such ring structure. Very satisfactory results may be obtained when two or more different halogens are present in the same molecule, ortho brom chlor benzene being a good example of such a compound. If the arcmatic compounds have been alkylated, they are often especially effective.

As a matter of convenience, the halogenated diphenyl and substituted diphenyls, as well as halogenated substituted benzenes where two or more phenyl groups are directly linked, may be inclusively referred to as halogenated polyphenyls.

the aryl type, i. e., compounds containing ben-' Some of the best examples of the aromatic solvents are:

Ortho-dichlor benzene Mono-chlor toluene Di-ethyl dichlor benzenes Di-ethyl tetrachlor benzenes Chlorinated diphenyl Chlorinated alkylated diphenyl Good examples of halogenated aliphatic hydrocarbons are:

Fluorinated pentane Fluorinated hexane Fluorinated octane Halogenated petroleum derivatives, particularl halogenated petroleum waxes.

Oxygen-bearing component B. Heterocyclic Type Compounds (1) Of the aromatic or allied type including derivatives of pyridine, quinoline, etc.

(2) Other types such as furane and its derivatives and derivatives of thiophene, pyrrole, etc.

The oxygen-bearing derivatives of the foregom ing compounds may also be classified according I have found that of the entire class of oxygen-bearing organic compounds usable as a component; in my improved solvent, as above defined, the halogenated compounds and preferably those of the aromatic series, are generally superior solvents for the oxidized polymerized hydrocarbon deposit, and that these solvents may be used in conjunction with the solvents for the unoxidized polymerized hydrocarbon deposit, also being compatible with the oil. Here again, compounds of the aromatic series with the halogen attached to the ring are favored.

However, a certain number of the oxygen-bearing aliphatic compounds have been found to be very effective.

The oxygen-bearing components may, for convenience, be classified as follows:

I. ALJPHATIC, OR CARBON CHAIN TYPE Oxygen-bearing derivatives of:

A. Hydrocarbons of the paraflin series;

B. Hydrocarbons of the olefine series; and- C. Hydrocarbons of the acetylene series. 11. ORGANIC RING TYPE (c) Naphthenes, such as naphthenic I 7 acid, etc. 1

(3) 01 mixed type such as derivatives of indene, hydrindene, hydranthracene, etc.

Of the class including the cycloto the nature of the attachment of the oxygen to the molecule,

I. Directly attached to one or more carbon atoms, as in the case of:

(1') Ethers and analogous compounds (2) Compounds containing the 4'1 --0 H radicle such as alcohols and other derivatives of carbinol (including phenols, cresols, naphthols, etc.)

(3) Compounds containing the carbonyl such as aldehydes, ketones, organic acids, esters and salts of organic acids, thio-acids and esters of thio-acids I Compounds in which oxygen forms a part'of a ring structure, e. g. compounds containing the furyl or hydrofuryl groups. Compounds with an inorganic radicle where the oxygen is directly attached to a carbon atom, e. g.

Arsenites Hypochlorites Phosphites Thiophosphates Thiophosphites p-hydroxylamines Borates II. Indirectly'attached through the means of some other atom, i. e., in the form organic radicle, e. g.. I

Arsenate Chlorate Chlorite Cyanate a-hydroxylamine Nitrate Nitrite Nitro Nitroso Oxime Perchlorate Phosphate Sulphate Sulphite Sulphinic acid Sulphone Sulphonic acid Sulphoxide Thiophosphate Thiophosphite Thio-sulphate (Note:This class includes salts of organic bases with inorganic oxy-acids.)

The following table indicates some of the compounds. which are especially suitable, halogenated or unhalogenated, as the case may be:

of an in- Organic oxygen compounds Ring compounds Unhalogenated Halogenated Aromatic phenols Phenol O-chlor henol.

Monoc or a-naphthol.

Chlor-resorcinols. -lar acids (preferably refined by distillation) Cyclohexyl phenol Alcohols; Benzyl alcohol Chlor benzyl alcohols.

Phenyl ethyl alcohol.

Aldehydes (less desir- Benzaldehyde able because of polymerization).

Ketones Acetophenone Monoehlor aeetophenone.

Benzophenone Monochlor benzophenone. Alkylated benzophenones, Alkylated chlor-benzophenones, e. g.: Methyl benzophenones Methyl chlor-benzophenones. Dunethyl benzophenon Dimethyl chlor-benzophenones. Ethylated benzophenone Ethylatod chlor-phenones. Propylated benzophenon Propylated chlor-benzophenones. Phenyl tolyl lretones Dinaphthyl ketone Amides Aeetanilide" Stearanilide Stear-chloranilides.

Acids Aromatic fatty acids, e g

Phenyl acetic ae1 Chlorphenyl acetic acids. Pheuyl stearic acl Chlorphenyl stearic acids.

Esters and salts Ethers Salicylic acid Phenyl acetate.

Butyl benzoate Di-methyl phthalat Di-ethyl phthalate Dibutyl p Methyl salicylate Diphenyl ether Phenyl ethyl ether Dixeny] ether Dina phthyl ether Alkylated diphenyl ether Chlor-salicylic acids.

Ethyl chlorbenzoates. Butyl chlorbenzoates. Di-methyl chlorphthalates. Di-ethyl chlorphthalates. Dibutyl chlorphthalates.

Methyl ehlor salicylatcs. Chlorbenzyl acetates.

Esters of ehlor-aromatic fatty acids, e. g.: I

Esters of ehlorphcnyl acetic and chlorphenyl stearic acids including the methyl, ethyl, butyl, lauryl. cetyl and ceryl esters; sodium and calcium chlorphenyl-stearates.

Chlorinated diphenyl ether. Chlorphenyl ethyl others. Chlorinated dixenyl ether. Chlorinated diuaphthyl ether. Alkylated chlor-diphenyl ether.

Oxygen-bearing heterocyclic compounds (1) Furane and derivatives, e. g.

Non-aromatic oxygen-bearing organic ring compounds Cycle-hexanol Cyclo-hexyl esters, e. g. cyclo-hexyl stearate,

cyclo-hexyl laurate, tri-cyclo-hexyl phosphate, tri-cyclo-hexyl phosphite Naphthenic acids Esters of naphthenic acids, e. g. methyl 55 naphthenates Tetrahydrofurfuryl alcohol and esters of it, e. g. tetrahydrofurfuryl acetate and stearate (2) Oxygen-bearing derivatives of thiophene and pyrrole, e. g. esters of thiophene carboxylic acids and esters of pyrrole carboxylic acids.

Chain compounds Unhalogenated Halogenated Alcohols Cetyl alcohol Carnaubyl alcohol Ceryl alcohol Esters and salts Methyl stea Butyl laetate Lauryl acetate.

Ceryl acetate."

Tri-lauryl phosphite.

Octyl alcohol M yricyl alcohol Methyl palmitate Tri-ethanol-amine acetate. Tri-lauryl phosphate..-"

Di-ethyl oxalate Fluorinated octyl alcohol. Fluorinated deeyl alcohol. Fluorinated layurl alcohol Fluorinated cetyl alcohol. Fluorinated carnaubyl alcohol. Fluorinatcd ceryl alcohol. Fluorinated montanyl alcohol. Fluorinated melissyl alcohol. Fluorinated myricyl alcohol.

Methyl dichlor palmitate. Methyl dichlor stcarate. Sodium chlorhydroxy-stcarate.

Chain compounds Unhalogenated Halogenated Esters and salts Di-eetyl oynlnfn Dl-ntyl oxalate Di-lauryl oxalate Sodium chlorhydroxy-stearate.

Di-ceryl nvnluha Dibutyl malrmatn Dibutyl ant-pinata Dibutyl tartrate Dilauryl tartrate Tributyl citrate trilauryl nitrate Tri-cthanol amine.-- Trl-butanol amine Dibuty] nfhannlnmine Hydroxy-amines Ethers Di ropylketone. Di utyl ketone Di-amyl ketone. Di-octyl ketone.

Palmitone. Stear Ketones Acids Propionic acid.

Dimethyl malonate Dimethyl succinate Dimethyl tartrate Butyric acid Chlorinated or fiuorinated:

Ethyl ether (notably B,

B dichlor ethyl ether). Butyl ether. Amyl ether.

Chlorinated or fluorinaterl:

Laurone.' Palmitone. Stearone.

Chlorinated or fluorinated:

Laurie acid. Palmitic acid.

Hydroxystearic acid Stearic acid.

,Chlorhydroxystearic acid.

atoms of chlorine per molecule, and has preferably been purified by vacuum distillation, or other means, is one of the most desirable solvents of this class; This solvent boils at a temperature Other examples of such compounds will be found in my co-pending applications Ser. Nos. 99,165 filed September 2, 1936, and 119,132 filed January 5, 1937. However, with these exceptions, the oxygen is generally preferred in the form of an organic radicle.

Of the specific compounds mentioned in this application, all are more or less effective, when incorporated in a hydrocarbon oil, to improve theabout 300C. without appreciable decomposition. 40 properties of the oil afiecting its use as a lubri- See my co-pending application Ser. No. 83,976.)

0f the above enumerated classes of o y enare more easily oxidized, and, therefore, less stable 7 than the non-condensed" multiple-ring type in which no carbon atoms are thus shared, the latter type is to be preferred. Poly-nuclear aromatic compounds (that is, those containing more than one ring) of the non-condl sed type are thus the more desirable of such aronic compounds.

It is to be noted that certain compounds of the class in which oxygen is in the form of an inorganic radical, have the additional advantage of inhibiting corrosion, and, therefore, otherwise corrosive halogenated oxygen-free organic compounds may be used in conjunction with them for service in lubricants. Notable examples of such compounds are the organic phosphates, of which tri-phenyl phosphate and tri-cresyl phosphate are good examples, and the phosphites,

Another preferred class of cant.

cant, altho in order to increase the sludge-solventicity to a maximum degree, it is preferable to employ combinations of them inaccordance with my present invention. However, many of the individual examples of compounds listed herein may be used alone as the sole addition to the hydrocarbon oil to effect considerable improvement in sludge-solventicity, as well as other properties of the oil afiecting its use as a lubri- All of the halogen compounds, for example, are efiective extreme pressure addition agents and the oxygen compounds are more or such as tricyclohexyl phosphite, tri-phenyl phosless effective to improve oiliness."

Preferred combinations to make up my new solvent include:

About 25% to o-dichlor benzene, ethyl chlor-benzenes, ethyl dichlor benzenes, or diethyl tetrachlor benzenes, with one or more of the following:

Hexachlor. diphenyl oxide Trichlor diphenyl oxide Monochlor benzophenone Benzophenone Methyl benzophenones Methyl chlorbenzophenones Phenyl acetate Phenol o-Phenyl phenol Cyclo hexanol Dibutyl phthalate Methyl salicylate Lauryl alcohol Methyl stearate Tri-ethanol amine Tri-ethanol amine acetate The chlorinated diphenyl oxide and other compounds referred to above are compounds containing an average number of chlorine atoms equivalent to that indicated.

In'cases where the lubricant is to be exposed to relatively high temperatures, it is of particular advantage to use compounds for both components of my new solvent which'are highly stable.

For use in the crankcases of internal combustion engines, it will usually be preferable to employ compounds which will not be subject to thermal decomposition when the lubricant is exposed to temperatures as high as 140 C., and more desir ably 170 C. or even 200 C. It is frequently advisable to employ compounds which will boil at atmospheric pressure without appreciable decomposition, preferably at temperatures above 140 C., ormore desirably 170 C. or even 200 C.

Chlorine, bromine, and fluorine are the halogens most desirable in both the oxygen-free and oxygen-containing compounds, fluorine forming particularly stable compounds which are no longer so difl'icult to prepare as formerly. Methods of preparing fluorine compounds which will be found satisfactory for use in my solvent are described, for instance, in U. S. Patent No. 2,013,- 030, Example IV, and in U. S. Patent No. 2,013,- 050, Example X. My invention, of course, is not to be considered as involving any particular method of preparation of the components nor is it intended to be limited by any such method or methods. Chlorine is the least expensive and most commercially available of all the halogens, and bromine is also satisfactory, although considerably more expensive, as is iodine.

The action of my new solvent composition may sometimes be improved by the use of a more or less complex mixture in the case of one or both of the two components used. This complexity may result from (1) the production of a plurality of compounds obtained by the halogenation process, as, for example, the chlorination of diphenyl or of diphenyl ether, either of which is capable of producing a large number of chlorinebearing compounds differing as to the number and location of the chlorine atoms in the molecule; or (2) the use of a product which, before halogenation, is a complex organic material, such as: a) chlorinated petroleum fractions; chlorinated parafiin wax; chlorinated commercial aromatic hydrocarbon products, such as mixed toluenes and xylenes, dead oil, and the like; for the halogenated oxygen-free component; and (b) non-drying fatty oils, such as sperm oil; tar

acids; and esters derived from mixed alcohols,

such as loro1; for the oxygen-bearing component.

It is also of advantage to use a combination of solvent components which will have a fairly wide range of volatility. This assures a certain and uniform solvent action, even if some of the components should be partially volatilized by unexpectedly high temperatures.

The oil base The lubricating oil which constitutes the oil Jase of my improved lubricant as noted above may be any mineral lubricating oil or synthetic equivalents. For use in the crankcases of internal combustion engines, the oil base will preferably be a highly refined mineral oil or synthetic hydro-carbon oil, and usually within the viscosity range of from about 30 to about 160 seconds Saybolt at 210 F., and more often within the range of 40 to 80.

Drastically refined oils, including those which have been solvent-extracted, the properties of whch have been greatly improved for certain use.., are now available. The particular properties which it has been found possible'to improve by such methods are, among others, the viscosity index and the sludge forming tendency of the oil. However, oils of this type, when subjected to heat and oxidation, are still subjectto the tendency to precipitate a resinous or varnish-like coating on the metal parts with which the oil comes in contact. This tendency is particularly serious in the crankcase lubrication of heavily loaded or high-speed internal combustion engines, notably of the aviation and Diesel types where the lubricant is exposed to relatively high temperatures.

For gear lubrication, the mineral oil need not Pennsylvania (paraflinic) Mid-Continent (mixed) or Coastal (naphthenic) The' parafiinic oils were, until recently, generally preferred for many uses because of their higher viscosity index, but improved refining methods, particularly various modifications of t e solvent-extraction type of refining process. have made it possible to produceoils of almost any desired viscosity index from any of the other crudes. For example, solvent-extracted oils from Coastal crudes with viscosity indices (Dean and Davis) from about to about 90, and from Mid-Continent crudes with viscosity indices of from about to about 110 are now commercially available. oils obtained from Pennsylvania crudes, has produced oils with a viscosity index ranging from about to about 120, or even higher.

As noted above, these oils may also have the sludge" forming tendency greatly reduced but are still susceptible to the formation of varnishlike deposits. For this reason, the Mid-Continent or naphthenic oils, refined by the more conventional methods, are still to a considerable extent, preferred for use where the resinous type of deposit is particularly undesirable as in the lubrication of Diesel engines, particularly those operated under high loads or at high temperatures.

For certain uses of this type, it is considered more desirable to use an oil which may. to a certain extent, be sludge forming but will not have the disadvantage of sticking rings or pistons because of its tendency to form resinous deposits. Min- The sam type of process, applied to crankcase.

refined oils usually used in gear lubrication. It.

is useful both in overcoming the tendency of the refined Pennsylvania and solvent-extracted types of oils to form varnish-like deposits, and to overcome the tendency of the naphthenic type'oils to form sludge. It may also be used to advantagein conjunction with detergents such as those described above. It should be noted that one or both of the components of my solvent may be of the type which also has detergent properties.

It is to be understood that among the oils which maybe used as the base of my improved compositions are included hydrogenatedas well as voltolized oils.

As the exact manner in which my solvent constituents act upon the "sludge is not entirely understood, I do not intend my invention to be restricted by any explanation or theory. However, it seems that the two types of solvents mutually aid one another in attacking the gummy "sludge forit has been found that the effectiveness' of their joint action is more than th cumulative effect of the two when used separately.

The presence ofthe halogen lowers the volatility and thus enables the use of a number of the most effective solvents which would otherwise be too highly volatile at engine temperatures. The presence of' the halogen also notably enhances the solvent action of the compounds and therefore makes available more effective compounds. The degree of halogenation may, however, reach an optimum beyond which further halogenation gives no improvement in the solvent action or may even cause a decline in efiectiveness.

The relative proportions of halogenated'oxygen-free organic constituents and oxygen-bearing organic constituents in the new solvent comprising my invention may vary within wide limits,

depending upon the particular materials used (a very minor proportion of the more active components at times being quite effective) the kind of oil to which the solvent is to be added, and

i the kind of engine employing the lubricant. The

erably only from about one to two, up to two to one. For most applications a lubricating composition containing a solvent comprising substantially equal amounts of each type has been found very satisfactory.

The amount of the solvent combination to be added to the oil will depend upon the type of oil and the type of engine using the lubricant, and

may vary over wide limits, for example, from about .001% to about 20% by weight based on the oil. To obtain a maximum of desirable characteristics in the lubricant, a proportion of from about .1% to about 3% of the combined solvent is usually of advantage while amounts up. to 5 or 10% are occasionally desirable and amounts up to 20% may often be used without unduly decreasing the viscosity of the lubricant.

Proper stability of the components of the solvent combination in' the lubricant is an important' factor. Since the materials are to be exposed to relatively high temperatures in. the crankcase, etc., they should be particularly resistant to thermal decomposition.

Resistance to hydrolysis is a 'most desirable characteristic because of the likelihood of a certain amount of moisture being present in the Under these conditions, easily hydrolyzed halogen compounds will tend to produce hydrogen halides which will cause corrosion of the parts of the engines with which they come in I contact. Although this tendency may be corrected to a certain extent by the use of proper inhibitors. 1

Elsewhere in this specification reference is made to the fact that the specifically identified addition agents contemplated for use may be incorporated in the lubricating composition of my invention in amounts up to 20% or for certain uses, in lesser amounts, for example, up to 10% or up to 5%.

Among the large number of classes of compounds disclosed herein will be found specific -examples which are not fully oil-soluble to the extent of the percentages above stated. Certain of such compounds will be-soluble to only a minor extent, for example, on the order of about 1%, and they, of course, are useful for the purpose herein specified up to the extent of their solubility. Still others are difficultly soluble to any extent, even minor, andrequire the use of special blending apparatus or even mutual solvents in order to embody the same in a composition in such form as. not to separate out. Among the large class of compounds identified will also be found certain specific examples which may not be soluble in mineral oil to any extent. Those will obviously not be useful for my purpose.-

Throughout the specification and the claims, therefore, I have employed the term oil-soluble as being a further limitation on the compounds which are useful in the compositions of my invention. Where the compound is soluble to on y a limited extent, i. e., less than the range specified within which the same may be employed, it will be understood, of course, that the use of such compound is covered only up to the extent of itssolubility.

The term soluble as used herein, is intended to indicate the ability to form not only true solutions but also any form of substantially permanently stable, homogeneous compositions when incorporated in the lubricating composition.

The superiority of my lubricant has been demonstrated commercially by its highly successful use in automobile, truck and bus engines. The solvent constituents may be most conveniently introduced into the mineral oil before such oil is placed in the crankcase, but this invention does not cover nor is it intended to be limited by any particular method of addition of the solvent constituents to the lubricant. Any practicable means of addition is intended to be within the scope of this invention. Other specific applications of this invention have been made and will occur to those acquainted with the art and this invention is intended to include all such applications.

To a mineral oil base are, therefore, added my solvent constituents comprising at least one representative of each of the two types of compounds disclosed to inhibit the formation and aid in removal of oil sludge. It is generally preferable, but not absolutely necessary, that at least one of the solvents be of the aromatic series. The two solvent compositions described have a cooperative dissolving effect, each enabling the other to work more quickly and completely.

This invention is equally applicable to other than automotive fields of lubrication and othr uses for my improved lubricant will be immediately apparent to those skilledin the art. This invention is intended to cover all such applies-- tions.

It is also to be noted that combinations of the type described are highly effective in increasing the extreme pressure characteristics of the lubricant, and thus my improved lubricant has the combined advantages of being sludge-resistant even in cold weather, and at the same time providing the safety of an extreme pressure lubricant.

The following are specific examples of lubricating compounds, in accordance with my invention, particularly useful as crankcase lubricants in internal combustion engines." These same compositions may advantageously be used also as spindle oils, hydraulic oils, compressor oils and the like, particularly under conditions which expose the lubricant to oxidation at high temperatures.

The base oil will preferably be a Pennsylvania motor oil (or other oil of high viscosity index) having a viscosity such that it will meet the specifications for an S. A. E. 10, 20, 30, 40, 50 or 60 motor oil. For crankcase lubrication, in most cases, I prefer the lower viscosity range as a base for my compositions, namely the S. A. E. 10, 20 and 30 oils. Other types of oils may be used instead of Pennsylvania oil in preparing these compositions, for example, Mid-Continent or naphthenic base oils.

In the following examples of lubricating compositions, I shall indicate only those addition agents, the use of which is the particular subjectmatter of the present invention. It will be understood that in each specific example, the remainder of the composition is substantially all mineral lubricating oil of the character above defined with the possible addition of minor amounts of further constituents such as means for improving the cold test, etc., as are commonly employed in lubricating compositions of this character. A

Example 1 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide Example 2 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.25% methyl stearate, and 0.25% butyl stearate Example 3 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.25% methyl dichlorstearate Example 4 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.12% methyl chlorsalicylate 0.1% methyl salicylate Example 5 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 1.0% calcium phenyl-stearate Example 6 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 1.0% calcium chlorphenyl-stearate Example 7 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% cyclo-hexyl stearate Example 10 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.25 benzophenone Example 11 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide' 0.25% methyl benzophenone Example 12 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% di-ethyl diphenyloxide I Example 13 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% dimethyl phthalate Example 14 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% dibutyl phthalate y Example 15 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.13% methyl salicylate Example 16 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.13% methyl chlorobenzophenone Example 17 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.13% cyclohexyl salicylate Example 18 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.13% cyclohexyl chlorsalicylate Example 19 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.1% tri-cyclohexyl phosphite Example 20 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.2% tri-cyclohexyl phosphate Example 21 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.25% butyl acetyl ricinoleate Example 22 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide ester) 0.06% di-ethylene glycol dichlorstearate (monoester) Example 23 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% cyelohexyl phenyl-stearate Example 24 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.5% cyclohexyl chlor-phenyl st'earate Example 25 0.5% orthodichlor benzene 0.5% hexachlor diphenyl oxide 0.25% methyl chlorbenzoate Example 26 1.0% o-dichlor benzene 0.5% butyl stearate Example 27 0.4%v o-dichlor benzene 0.13% triphenyl phosphite 0.4% hexachlor diphenyl oxide Example 28 0.3% o-dichlor benzene 0.06% tricyclohexyl phosphite 0.3% hexachlor diphenyl oxide Example 29 0.25 o-dichlor benzene 0.3% tri-cresyl phosphate 0.25% hexachlor diphenyl oxide Example 30 0.15% o-dichlor benzene 0.03% di-lorol phosphate 0.16% tri-phenyl phosphite 0.15% hexachlor diphenyl oxide Example 31 1.0% o-dichlor benzene 0.5% methyl stearate 0.5% hexachlor diphenyl oxide Example 32 0.25% o-dichlor benzene 0.25% methyl dichlor benzophenone Example 33 0.4% o-dichlor benzene 0.02% methyl salicylate 0.4% hexachlor diphenyl oxide 0.2% methyl chlor-salicylate' Example 34 0.25% o-dichlor benzene 0.25% di-ethyl tetrachlor benzene 0.25% methyl stearate 0.25% butyl stearate 0.5% hexachlor diphenyl oxide Example 35 0.5% di-ethyl tetrachlor benzene 0.5% hexachlor diphenyl oxide 0.25% methyl dichlorstearate Example 36 0.5% di-ethyl tetrachlor benzene 0.5% hexachlor diphenyl oxide 0.25 cyclohexyl diehlorstearate Example 37 0.5% di-ethyl tetrachlor benzene 0.25% methyl chlor-salicylate Example 38 0.5% di-ethyl tetrachlor benzene 0.25% cyelohexyl chlor-salicylate Example 39 0.5% di-ethyl tetrachlor benzene 0.5% hexachlor diphenyl oxide 1.0% calcium chlor-phenyl-stearate Example 40 0.5% di-ethyl tetrachlor benzene 0.5% hexachlor diphenyl oxide 0.5% cyclohexyl chlor-phenyl-stearate Example 41 0.5% di-ethyl tetrachlor benzene 1.0% calcium phenyl-stearate 0.5% hexachlor diphenyl oxide Example 42 0.25% ,o-dichlor benzene 0.25% di-ethyl tetrachlor benzene 0.5% hexachlor diphenyl oxide 0.25% methyl dichlorstearate Example 43 1.0% o-dichlor benzene 0.5% o-dichlor benzene 0.5% ethylated chlorinated naphthalene 0.5% hexachlor diphenyl oxide Example 49 1.0% ethylated chlorinated naphthalene 0.5% hexachlor diphenyl-oxide 0.25% methyl dichlorstearate Example 50 0.25% o-dichlor benzene 0.25% di-ethyl tetrachlor benzene 0.25% methyl dichlorstearate Example 51 0.5% di-ethyl tetrachlor benzene 0.5% methyl dichlorstearate' (Note.Hexachlor diphenyl oxide, referred to r in the above examples, consists of the vacuum distilled fraction of chlorinated diphenyl oxide which has an average of six chlorine atoms per molecule.)

Specific examples of lubricating compounds according to my invention, which are suitable for use in gear lubrication and the like, are asfollows:

The base oil in this case will be a gear oil having a viscosity such that it will meet with the specifications forS. A. E. number 80, 90, 110, 160 or 250 gear oil and may be prepared by blending two or more stocks consisting of bright stocks, steam-refined stocks or neutral oils, to give the desired characteristics. In most cases, I prefer for my purpose a base oil which has a relatively high viscosity index such as may be obtained by using Pennsylvania oils.

Similarly as in connection with the examples of lubricating compositions which have been found useful as crankcase lubricants,'I shall in-' dicate in the following examples of gear lubricants only those addition agents about which the present invention is primarily concerned. It is to be understood, of course, that the gear lubricants given below may contain, in addition to the mineral oil specified above to make up the entire composition, minor amounts of other constituents such as are commonly employed in gear lubricants, for example,,thickening agents, such as soaps, etc.

Example 52 Per cent Chlorinated parafiin wax (containing about 40% chlorine) 8 Butyl stearate 1 Example 53 Chlorinated parafiin wax 6 Tricresyl phosphate 1 Example 54 Chlorinated retene oil 4 Dilorol phosphate 0.1 Tri-cresyl phosphate 1 Easample 55 I Chlorinated parafiin wax L 8 Di(chlorbenzyl) disulphide" 2 Tricresyl phosphate 1 Example 56 Chlorinated paraffin wax 7.5 Chlorbenzyl thiocyanate 1.5 Tricresyl phosphate 1 Example 57 Chlorinated paraffin wax 8 Tricresyl thiophosphate, (C'zH1O) 3P5 1 The lubricating compositions of the present invention will be foundadmirably suited as addition agents for internal combustion engine fuels. When the fuel to which these compounded lubricants are added is a liquid hydrocarbon boiling within the gasoline range the lubricating composition will preferably contain a total of from about 2% to about 10% and even up to about of the addition agents, i. e. the halogenbearing oxygen-free organic compound and the organic oxygen compound which characterize the lubricating compositions referred to above. Such compounded lubricant is then added to the lighter hydrocarbon fuel in quantities varying from about 0.05% to about 1.50% by volume. The optimum amount of lubricant added to the fuel will be found to be in the vicinity of about 0.30%, i. e. in the range from about 0.15% to about 0.60%.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the materials employed, provided the ingredients stated by any of the following claims or the equivalent of such stated ingredients be employed.

1', therefore, particularly point out and distinctly claim as my invention:

1. A lubricating composition comprising at least 80% refined mineral lubricating oil with the properties of such composition affecting its use as a lubricant improved by incorporating therein a total of from about .1% to about based on the amount of mineral lubricating oil of both an oil-soluble halogen-bearing oxygenfree organic compound and an oil-soluble organic oxygen compound, said compounds being I ofthe type which will not substantially evaporate from such lubricating composition at ordinary temperatures.

2. A- composition in accordance with claim 1 in which the oxygen-bearing compound is a halogenated compound.

3. A composition in accordance with claim 1 in which the oxygen-bearing compound is a chlorinated compound.

4. A composition in accordance with claim 1 in which the oxygen-bearing compound is an ether.

5. A composition in accordance with claim 1' in which the oxygen-bearing compound is an acid.

6. A composition in accordance with claim 1 in which the oxygen-bearing compound is an ester.

'7. The method of reducing the tendency of a lubricating composition which consists essentially of refined mineral lubricating oil to-deteriorate as by way of producing sludge or gummy or varnish-like deposits which comprises blending therewith an effective amount less than about 20%, based on the amount of such mineral lubricating oil of both an oil-soluble halogenbearing oxygen-free organic compound and an oil-soluble organic oxygen compound, said compounds being of the type which will not substantially evaporate from such lubricating composition at ordinary temperatures.

8. The method of reducing the tendency of a lubricating composition which consists essentially of refined mineral lubricating oil to deteriorate as by way of producing sludge or gummy or varnish-like deposits which comprises blending therewith a total of about .001% to about 20%, based on the amount of such mineral lubricating oil of both an oil-soluble halogen-bearing oxygen-free organic compound and an oil-soluble 'organic oxygen compound, said compounds being of the type which will not substantially evaporate from such lubricating composition at ordinary temperatures and being present in a ratio of from about 1 to 10 up to about 10 to 1.

9. In the art of making lubricating oils the method which comprises blending mineral lubricating oil with a total of from about 0.1% to about 20%, based on the amount of mineral lubricating oil of both an oil-soluble halogen-bearing oxygen-free organic compound and an oilsoluble organic oxygen compound, said compounds being of the type which will not substantially evaporate from such lubricating composition at ordinary temperatures.

10. In the art of making petroleum lubricating oils, the method which comprises adding to petroleum oil a substantial quantity, i. e. a total less than about 20%, of both an oil-soluble halogenbearing oxygen-free organic compound and an oil-soluble organic oxygen compound, said compounds being of the type which will not substantially evaporate from such lubricating composition at ordinary temperatures and being present in amount suflicient to materially increase the extreme pressure characteristics of the lubricant and at the same time materially increase the resistance of the composition to sludging.

11. A composition in accordance with claim 1 in which the oxygen-bearing compound is a saturated organic compound.

12. A composition in accordance with claim 1 in which the oxygen-bearing compound is chlorinated stearic acid.

13. A composition in accordance with claim 1 in which the oxygen-bearing compound is methyl chlor salicylate.

14. A composition in accordance with claim 1 in which the oxygen-bearing compound is hexachlor diphenyl oxide.

15. Acomposition in accordance with claim 1 in which the oxygen-bearing compound is a de- Iivative of an acid containing an inorganic substituent.

16. A composition in accordance with claim 1 in which the oxygen-bearing compound is an ester containing an inorganic substituent.

CARL 15'. PRU'l'I'ON. 

